Tarxien & Hypogeum:

These very impressive temples – particularly the Hypogeum which represents an underground “mirrow“ complex of Tarxien – are located right in the city and are not really easy to find by car or by bus, or on foot. (A little known fact is that Livingstone and Stanley got lost there for 17 years trying to find the bus stop!); additionally, there are only a limited number of visitors allowed in the Hypogeum per day, visiting the place is only possible within the guided tours, and tickets need to be booked in advance (e.g. at the Archaeological Museum; these restrictions apply only to the Hypogeum, not to Tarxien).